On Mon, Sep 15, 2003 at 02:35:58AM -0400, JondZ wrote:
> alternatively, if you need to use telnet , open it but
> control it thru tcp wrappers (/etc/xinetd.d/telnet in
> newer redhat).  I use telnet but allow only allow hosts
> from my local net.  Works great.
> 

Until someday someone decides to install a password sniffer on a box on
your local network and sees all of your passwords going by in the clear.
It is then a simple matter to hijack one of your tcp wrappers trusted
hosts and access your supposedly "safe" host.  Or if someone decides to
mount an IP spoofing attack and pretends to be the target to one of your
wrapped hosts (still possible with ssh, but not if you use it the way it
is supposed to be used).  IP addresses should never be considered
trusted, not unless there is a cryptographic certificate of some sort
standing behind it.  Granted ssh does a less than optimal job of
managing these trust relationships (the old versions of SSH blindly
added certificates to the ~/.ssh/known_hosts file for instance), but it
at least provides a framework on which you can do this.  Strong
authentication is an absolute necessity in this day and age, and getting
into bad habits in this respect on what you might mistakenly feel are
"safe" local networks ay translate into those same bad habits being used
on dangerous public networks.  In my mind, that's a good enough reason
to deprecate the protocol altogether and never use it at all.

Better not to use telnet at all, ever again.  There are decent, Free ssh
clients available even for lesser OSes like Windows that are better than
the really terrible telnet client that MS appears to have shipped along
with Windows as an afterthought, so that is no longer an excuse.  The
only good telnet or ftp is a Kerberized one.

--
Philippine Linux Users' Group (PLUG) Mailing List
[EMAIL PROTECTED] (#PLUG @ irc.free.net.ph)
Official Website: http://plug.linux.org.ph
Searchable Archives: http://marc.free.net.ph
.
To leave, go to http://lists.q-linux.com/mailman/listinfo/plug
.
Are you a Linux newbie? To join the newbie list, go to
http://lists.q-linux.com/mailman/listinfo/ph-linux-newbie

Reply via email to